The Great Deep Sea is a massive, ornate harpoon-like weapon with a twisted, organic shape resembling the tentacles of a deep-sea creature. Its shaft is made of dark, weathered metal with intricate engravings of oceanic horrors, while the blade is a shimmering, translucent blue crystal that glows faintly in the dark. The weapon's surface features a combination of smooth, polished areas and rough, textured sections that mimic the scales of a sea monster.